Nearby Exoplanets Options

[JRehling]

There have been a few topics in recent years pertaining to exoplanets found circling nearby red dwarfs, particularly Proxima Centauri and Trappist-1. There's a new one to report, and I thought I'd give the topic a more general scope rather than specific to this one.

The star in question is Ross 128, and the planet's solar flux is between that of Earth and Venus. There's a good chance that this is potentially the most "habitable" exoplanet yet found, and is happily quite close (13th closest system), so that telescopes will be able to separate the light of the planet from that of the star. This is a circumstance that only a few nearby stars will permit in the foreseeable future, so Ross 128 is likely to figure large in our exoplanet studies over the next century.

https://www.eso.org/public/archives/release...36/eso1736a.pdf

[Ron Hobbs]

Excellent! Thank you for the link to the article.

Here is a link to the ESO release, which has cool artistic impressions videos.

https://www.eso.org/public/news/eso1736/

I look forward to hearing more about this system.

[JRehling]

A quick look outward:

Ross 128 is the 8th closest single red dwarf star. So far, we know of two ~earthsized planets in their ~HZs. Not a significant sample, and we don't know how many are yet to be found, but this is certainly suggestive that about a third of such stars have such planets. (The Doppler method can easily miss planets in orbits more or less perpendicular to our line of sight.) The true number may be much higher, because we don't have clear negatives yet on the other 6 of those 8.

Now, between Ross 128 and 20 light years out, there are 36 more single red dwarfs. Between 20 and 30 light years out, there are 75 more. And of course, there are 6 farther than Proxima Centauri and closer than Ross 128, making 117 more red dwarfs within 30 LY. If a third of those have such planets, we have dozens yet to find.

This says seriously good things about the sample we are going to be able to examine with followup studies.

The closest such transiting planet, however, may be quite a bit farther, but distance won't be a serious impediment for detection and characterization of those.

And, of course, there are also many multiple systems and bigger, hotter stars. We already know that the closest single non-red dwarf, Epsilon Eridani, probably has planets.

It's going to be an interesting few decades ahead for studying nearby terrestrial planets.